The three Islamists who killed eight people after driving a van into pedestrians on London Bridge and then attacking nearby revelers had initially tried to hire a 7.5 tonne (8.3 ton) truck, the head of the United Kingdom capital's counter-terrorism unit said on Friday.
Detectives suspect the carnage inflicted could have been even worse if Khuram Butt had not failed to secure the vehicle because his payment did not go through.
Image caption Eight people were killed in the attack last Saturday.
The three men drove up and down the London Bridge twice before ultimately carrying out the attack, police said. But his attempt echoed last July's attack in Nice, France, when a 19-tonne truck was driven into crowds, killing 86 people.
Police revealed the attempt to rent the lorry was made hours before they staged the attack, with the trio instead using a rented van to run people over, and then going on a stabbing rampage, killing eight and wounding 48.
Armed officers arrived and shot the suspected attackers dead.
Commander Dean Haydon, of Scotland Yard's counter-terrorism command, said: "Concerningly, Butt had earlier attempted to hire a 7.5-tonne lorry that same morning".
"Khuram Shazad Butt was known to the police and MI5", the Metropolitan Police said in a statement on Monday.
"We're not looking for a wider network", said Haydon, adding, however, that authorities are still trying to figure out how exactly this "diverse bunch" came together to commit the terrorist act. Two blowtorches were also found.
Cole, 41, said the attack was "the most challenging, most intense situation I've dealt with" in an 18-year police career.
They found a number of office chairs and a suitcase, and believe that the attackers had told family they were using the van to move as a cover story.
Tape was wrapped around the handles.
While the Islamic State (IS, formerly ISIS/ISIL) has claimed the responsibility for the attack, Haydon said police have so far not found evidence to suggest it was coordinated from overseas, or that the assailants were part of a larger network.
Police have discovered the gang used a bedsit, above a bookie's in Barking, east London, as a safe house, rented by Redouane in April. An undated handout photo issued by the Metropolitan Police, London, and made available Saturday, June 10, 2017, of the interior of the van used in the London Bridge attacks of Saturday June 3 which killed several pe.
In the residence, police found the English-language copy of the Qur'an opened at a page describing martyrdom, as well as pieces of cloth which appeared to match the material wrapped around the Molotov cocktails and water bottles similar to those used in the fake suicide vests, police said.
Detectives have been give more time to question a man arrested in connection with the attack.
Thirteen have been released without charge, while five men aged between 27 and 30 remain in custody.
"I then saw a few injured people who were bleeding, including a man who had been stabbed in the stomach and we got them to safety in the pub".
"You should feel reassured by that, but please don't give in to terrorists and let's go about our daily business".
Butt was still one of 3,000 "subjects of interest" considered the most unsafe potential threats in the country and was a figure in one of just 500 active counter-terrorism investigations, the sources said.
Butt, once seen in a documentary called "The Jihadis Next Door", had been repeatedly reported to police for his violent behavior and reports from a neighbor who said he was trying to lure young kids to radical Islam.
Butt was also arrested for fraud last October but was about to be told by prosecutors he would face no further action.